With the rapid development of display technology, Thin Film Transistor Liquid Crystal Display (TFT-LCD), as a flat panel display device, has been increasingly applied to the field of high-performance display due to its small size, low power consumption, no radiation and relatively low production cost.
A manufacturing process of a TFT-LCD display panel comprises preparing an array substrate and a color filter substrate and then aligning the array substrate and the color filter substrate to form a cell. As illustrated in FIG. 1, a typical TFT array substrate comprises a transparent substrate 11; and a TFT gate 120, a gate insulation layer 13, an active layer 14, a TFT drain 121 and a TFT source 122 located at both sides of the active layer 14; a first passivation layer 15 located on surfaces of the active layer 14, the TFT drain 121 and the TFT source 122, a plate-shaped first transparent electrode 16 located on a surface of the first passivation layer 15, and a second passivation layer 17 and a slit-shaped second transparent electrode 18 formed sequentially on a surface of the first transparent electrode 16 located sequentially on a surface of the transparent substrate 11.
In existing technologies, as shown in FIG. 1, portions of the semiconductor active layer 14 and the gate insulation layer 13 are not covered by the TFT source 122 or the TFT drain 121 (shown as the area A in FIG. 1). Thus light directly irradiates the interface between the semiconductor active layer 14 and the gate insulation layer 13 without being reflected by a metal layer. In this way, the interface will be activated by external ambient light so that shallow energy levels of defects occur, carrier trapping effect takes place at the interface between the semiconductor active layer 14 and the gate insulation layer 13, and then relatively large leakage current is generated between the semiconductor active layer 14 and the gate insulation layer 13, thus affecting the stability of TFT and reducing display effect of the display device.